1 // SPDX-License-Identifier: GPL-2.0
7 #include <linux/refcount.h>
8 #include <linux/rbtree.h>
9 #include <linux/zalloc.h>
14 struct rb_node rb_node;
18 /* Should perhaps be moved to struct machine */
19 static struct rb_root comm_str_root;
20 static struct rw_semaphore comm_str_lock = {.lock = PTHREAD_RWLOCK_INITIALIZER,};
22 static struct comm_str *comm_str__get(struct comm_str *cs)
24 if (cs && refcount_inc_not_zero(&cs->refcnt))
30 static void comm_str__put(struct comm_str *cs)
32 if (cs && refcount_dec_and_test(&cs->refcnt)) {
33 down_write(&comm_str_lock);
34 rb_erase(&cs->rb_node, &comm_str_root);
35 up_write(&comm_str_lock);
41 static struct comm_str *comm_str__alloc(const char *str)
45 cs = zalloc(sizeof(*cs));
49 cs->str = strdup(str);
55 refcount_set(&cs->refcnt, 1);
61 struct comm_str *__comm_str__findnew(const char *str, struct rb_root *root)
63 struct rb_node **p = &root->rb_node;
64 struct rb_node *parent = NULL;
65 struct comm_str *iter, *new;
70 iter = rb_entry(parent, struct comm_str, rb_node);
73 * If we race with comm_str__put, iter->refcnt is 0
74 * and it will be removed within comm_str__put call
75 * shortly, ignore it in this search.
77 cmp = strcmp(str, iter->str);
78 if (!cmp && comm_str__get(iter))
87 new = comm_str__alloc(str);
91 rb_link_node(&new->rb_node, parent, p);
92 rb_insert_color(&new->rb_node, root);
97 static struct comm_str *comm_str__findnew(const char *str, struct rb_root *root)
101 down_write(&comm_str_lock);
102 cs = __comm_str__findnew(str, root);
103 up_write(&comm_str_lock);
108 struct comm *comm__new(const char *str, u64 timestamp, bool exec)
110 struct comm *comm = zalloc(sizeof(*comm));
115 comm->start = timestamp;
118 comm->comm_str = comm_str__findnew(str, &comm_str_root);
119 if (!comm->comm_str) {
127 int comm__override(struct comm *comm, const char *str, u64 timestamp, bool exec)
129 struct comm_str *new, *old = comm->comm_str;
131 new = comm_str__findnew(str, &comm_str_root);
136 comm->comm_str = new;
137 comm->start = timestamp;
144 void comm__free(struct comm *comm)
146 comm_str__put(comm->comm_str);
150 const char *comm__str(const struct comm *comm)
152 return comm->comm_str->str;